RegionDescPtr selectHotRegion(TransID transId,
MCGenerator* mcg) {
auto const profData = jit::profData();
assertx(profData);
auto const& func = *profData->transRec(transId)->func();
FuncId funcId = func.getFuncId();
TransCFG cfg(funcId, profData, mcg->srcDB());
assertx(regionMode() != RegionMode::Method);
RegionDescPtr region;
HotTransContext ctx;
ctx.cfg = &cfg;
ctx.profData = profData;
ctx.tid = transId;
ctx.maxBCInstrs = RuntimeOption::EvalJitMaxRegionInstrs;
switch (pgoRegionMode(func)) {
case PGORegionMode::Hottrace:
region = selectHotTrace(ctx);
break;
case PGORegionMode::Hotblock:
region = selectHotBlock(transId, profData, cfg);
break;
case PGORegionMode::WholeCFG:
case PGORegionMode::HotCFG:
region = selectHotCFG(ctx);
break;
}
assertx(region);
if (Trace::moduleEnabled(HPHP::Trace::pgo, 5)) {
std::string dotFileName = std::string("/tmp/trans-cfg-") +
folly::to<std::string>(transId) + ".dot";
std::ofstream outFile(dotFileName);
if (outFile.is_open()) {
cfg.print(outFile, funcId, profData);
outFile.close();
}
FTRACE(5, "selectHotRegion: New Translation (file: {}) {}\n",
dotFileName, region ? show(*region) : std::string("empty region"));
}
always_assert(region->instrSize() <= RuntimeOption::EvalJitMaxRegionInstrs);
if (region->empty()) return nullptr;
return region;
}
RegionDescPtr selectHotRegion(TransID transId,
MCGenerator* mcg) {
assertx(RuntimeOption::EvalJitPGO);
const ProfData* profData = mcg->tx().profData();
auto const& func = *(profData->transFunc(transId));
FuncId funcId = func.getFuncId();
TransCFG cfg(funcId, profData, mcg->tx().getSrcDB(),
mcg->getJmpToTransIDMap());
TransIDSet selectedTIDs;
assertx(regionMode() != RegionMode::Method);
RegionDescPtr region;
HotTransContext ctx;
ctx.cfg = &cfg;
ctx.profData = profData;
ctx.tid = transId;
ctx.maxBCInstrs = RuntimeOption::EvalJitMaxRegionInstrs;
switch (pgoRegionMode(func)) {
case PGORegionMode::Hottrace:
region = selectHotTrace(ctx, selectedTIDs);
break;
case PGORegionMode::Hotblock:
region = selectHotBlock(transId, profData, cfg);
break;
case PGORegionMode::WholeCFG:
case PGORegionMode::HotCFG:
region = selectHotCFG(ctx, selectedTIDs);
break;
}
assertx(region);
if (Trace::moduleEnabled(HPHP::Trace::pgo, 5)) {
std::string dotFileName = std::string("/tmp/trans-cfg-") +
folly::to<std::string>(transId) + ".dot";
cfg.print(dotFileName, funcId, profData, &selectedTIDs);
FTRACE(5, "selectHotRegion: New Translation {} (file: {}) {}\n",
mcg->tx().profData()->curTransID(), dotFileName,
region ? show(*region) : std::string("empty region"));
}
always_assert(region->instrSize() <= RuntimeOption::EvalJitMaxRegionInstrs);
return region;
}
/**
* Regionize a func, so that each node and each arc in its TransCFG is
* "covered". A node is covered if any region contains it. An arc T1->T2
* is covered if either:
*
* a) T1 and T2 are in the same region R and R contains arc T1->T2.
* b) T2 is the head (first translation) of a region.
*
* Basic algorithm:
*
* 1) sort nodes in decreasing weight order
* 2) for each node N:
* 2.1) if N and all its incoming arcs are covered, then continue
* 2.2) select a region starting at this node and mark nodes/arcs as
* covered appropriately
*/
void regionizeFunc(const Func* func,
MCGenerator* mcg,
RegionVec& regions) {
const Timer rf_timer(Timer::regionizeFunc);
assertx(RuntimeOption::EvalJitPGO);
PGORegionMode regionMode = pgoRegionMode(*func);
auto const funcId = func->getFuncId();
auto const profData = mcg->tx().profData();
TransCFG cfg(funcId, profData, mcg->tx().getSrcDB(),
mcg->getJmpToTransIDMap());
if (Trace::moduleEnabled(HPHP::Trace::pgo, 5)) {
auto dotFileName = folly::to<std::string>(
"/tmp/func-cfg-", funcId, ".dot");
cfg.print(dotFileName, funcId, profData, nullptr);
FTRACE(5, "regionizeFunc: initial CFG for func {} saved to file {}\n",
funcId, dotFileName);
}
TransCFG::ArcPtrVec arcs = cfg.arcs();
std::vector<TransID> nodes = cfg.nodes();
std::sort(nodes.begin(), nodes.end(),
[&](TransID tid1, TransID tid2) -> bool {
if (regionMode == PGORegionMode::WholeCFG ||
regionMode == PGORegionMode::HotCFG) {
auto bcOff1 = profData->transStartBcOff(tid1);
auto bcOff2 = profData->transStartBcOff(tid2);
if (bcOff1 != bcOff2) return bcOff1 < bcOff2;
}
if (cfg.weight(tid1) != cfg.weight(tid2)) {
return cfg.weight(tid1) > cfg.weight(tid2);
}
// In case of ties, pick older translations first, in an
// attempt to start loops at their headers.
return tid1 < tid2;
});
TransCFG::ArcPtrSet coveredArcs;
TransIDSet coveredNodes;
TransIDSet heads;
TransIDToRegionMap headToRegion;
RegionToTransIDsMap regionToTransIds;
regions.clear();
for (auto node : nodes) {
if (!coveredNodes.count(node) ||
!allArcsCovered(cfg.inArcs(node), coveredArcs)) {
TransID newHead = node;
FTRACE(6, "regionizeFunc: selecting trace to cover node {}\n", newHead);
TransIDSet selectedSet;
TransIDVec selectedVec;
RegionDescPtr region;
switch (regionMode) {
case PGORegionMode::Hottrace:
region = selectHotTrace(newHead, profData, cfg,
RuntimeOption::EvalJitMaxRegionInstrs,
selectedSet, &selectedVec);
break;
case PGORegionMode::WholeCFG:
case PGORegionMode::HotCFG:
region = selectHotCFG(newHead, profData, cfg,
RuntimeOption::EvalJitMaxRegionInstrs,
selectedSet, &selectedVec);
break;
case PGORegionMode::Hotblock:
always_assert(0 && "Invalid value for EvalJitPGORegionSelector");
}
FTRACE(6, "regionizeFunc: selected region to cover node {}\n{}\n",
newHead, show(*region));
profData->setOptimized(profData->transSrcKey(newHead));
assertx(selectedVec.size() > 0 && selectedVec[0] == newHead);
regions.push_back(region);
heads.insert(newHead);
regionToTransIds[region] = selectedVec;
headToRegion[newHead] = region;
markCovered(cfg, region, selectedVec, heads, headToRegion,
coveredNodes, coveredArcs);
FTRACE(6, "regionizeFunc: selected trace: {}\n",
folly::join(", ", selectedVec));
}
}
assertx(coveredNodes.size() == cfg.nodes().size());
assertx(coveredArcs.size() == arcs.size());
sortRegions(regions, func, cfg, profData, headToRegion, regionToTransIds);
if (debug && Trace::moduleEnabled(HPHP::Trace::pgo, 5)) {
FTRACE(5, "\n--------------------------------------------\n"
"regionizeFunc({}): computed regions:\n", funcId);
for (auto region : regions) {
FTRACE(5, "{}\n\n", show(*region));
}
}
}
